Some documents of the state of art disclose catheters that are provided with connection devices located outside of the body of a patient with particular respect to the problem of maintaining aseptic conditions.
Patent EP 0 070 087 discloses a connector member, comprising a valve adapted to a ultraviolet antimicrobial irradiation, the connector member being able to connect a permanent catheter to an external equipment. The above patent describes especially materials to be used to make the connector member, materials that have to be permeable to ultraviolet rays and, at the same time, resistant to them. However, said patent considers neither any closure means for the connector member when the latter is not connected to an external equipment, nor any problem relevant to the replacement of a permanent catheter in case of need.
Patent EP 0 227 219 describes a closure plug for an end of a permanent catheter, the closure plug being formed by two detachable parts, the one for keeping aseptic the external side of said end, the other the internal side. For this purpose a material impregnated with an antiseptic liquid is used.
U.S. Pat. No. 5,324,274 discloses a dual lumen vascular access catheter having a main elongated body defining first and second lumens, and a connection structure which includes coupling means attaching the structure to the main body. First and second channels extend from the respective first and second lumens for attaching the catheter to equipment. Further, first and second rotary valves are positioned in the first and second channel. The valves include rotatable operators for providing a ready visual indication of the positions of the valves. U.S. Pat. No. 5,324,274 deals with the connection between equipment and not permanent catheter and then does not face implantation and replacement problems.
The present invention relates to permanent catheters being used for example in dialysis and chemotherapy. Such catheters, made of a deformable, biocompatible material, can have a single lumen or a dual lumen, i.e. two ways. In the to-day permanent catheters near the external end thereof, there is a so called catheter cuff in the form of a thickness. The cuff, that can be made by pure silicone or Dacron filaments, is positioned in the subcutaneous tissue when the same catheter is being implanted. Once the body has developed a reactive fibrous tissue around the catheter, the cuff acts to anchor the catheter to the subcutaneous tissue, preventing or limiting a displacement or an accidental unthreading of the catheter. In the cuffs made of Dacron, the reaction of the subcutaneous tissue to the cuff also constitutes an effective barrier to the bacterial progression along the catheter, and then a limitation to infections. In the most external ends of the catheters, beyond the cuffs, there are end portions, sometimes made of a material different from that one of the catheter, in any case biocompatible and elastic, being provided with standard connectors known as “Luer Lock”, which allow catheters to be connected to blood lines of an equipment, for example a dialysis equipment.
These end portions are provided with suitable threaded closure plugs and small clips. The clips once closed squeeze the same end portions and achieve a further safety closure. At last the clips yields the material of the end portion with consequent break, if any, thereof.
The assembly of catheter, cuff, end portion and clip, has several drawbacks, such as, for example, a chronic exposure of the catheter and end portions to the saprophytic bacterial flora existing in the cute of the patient. Up to now the permanent catheters of the above type are fixed sub cute by a cuff; in their extracorporeal section, the permanent catheters are easily attached and infected by a series of pathogen agents as the catheters have to be handled and maneuvered by the nursing.
Initially, the bacterial flora colonizes and then infects the same catheter, first in its exit zone from the cute and then in the internal track thereof, in the subcutaneous tunnel until the catheter enters a vein, obliging its replacement in order to prevent a real septicemia to be developed. As the cuff is integral with the catheter on one side and is incorporated in the subcutaneous reactive tissue on other side, the catheter must be replaced by a surgical operation. In fact, the cuffs being integral with the catheter have to be unbridled from the subcutaneous tissue.
The noise to the patient by the external end portions that are too long and approximately protected by gauzes being wrapped up the external end portions and fixed thereto by plasters is not to be neglected. In a likely way these portions constituted by the external parts of the catheters and by Luer Lock connectors, can get entangled in dresses. The external end portions being free of moving cause esthetical inconveniences due to their cumbersome appearance and can be unintentionally damaged or torn away in sleep or further accidentally opened by the patient without realising and calling for help.